Electrical stress probing recovery efficiency of 28nm HK/MG nMOSFETs under different nitrogen concentration in nitridation

Under the same nitridation annealing treatment, the device performance for the lower nitrogen concentration in high-k dielectric treatment seems better than that with the higher one. In this stress test combining the recovery test, the recovery efficiency and the degradation rate in lower N
₂
concentration is more impressive than that with higher one, too. These results demonstrate the adequate N
₂
concentration can contribute the optimal electrical performance for the high-k dielectric as gate material.